report of the group on tripping of multiple trippings in ... report.pdf · report of the group on...

Report of the Group

On

Tripping of multiple trippings in and around 220 kV Samaypur Sub-Station of BBMB

1.0 Background

1.1 Multiple tripping occurred at 220 kV Samaypur sub-station of BBMB on 09.06.2016.

1.2 NRPC, vide their Order No NRPC/OPR/105/11/2016/ dated 10.06.2016 constituted a group to analyse the possible causes and suggest the remedial measures to avoid recurrence of such tripping in future. The members of the group constituted are given as under:

1. Sh. Hemant K. Pandey SE, NRPC……………Chairperson 2. Sh. Rajiv Porwal DGM, NRLDC 3. Sh. M.K.Singhal SE, RRVPNL

2.0 Multiple element tripping at 220kV Samaypur station on 9th Jun 2016 at 14:27hrs

A. Event Summary: At 14:27:20:599 hrs. of 9th Jun 2016, Yellow phase CT (current transformer) of 220kV Samaypur-Palwal Circuit-I at Samaypur (BBMB) end busted & caught fire. It resulted into failure of all three phase CB of the same line and created a bus fault for Bus-1. Bus Bar Protection for Bus-1 of 220kV Samaypur (BBMB) didn’t operate and all 220kV connected lines tripped on Z-2 / Z-3 distance protection in respective duration from remote end. All four 400/220kV ICTs also tripped in backup earth fault protection. 400kV Ballabhgarh-Gurgaon line tripped from Gurgaon end on Z-3 distance protection. 220kV Faridabad-Palla circuit-1 tripped from Faridabad end due to PLCC carrier mal-operation. 220kV Faridabad generation islanded from the grid with the load of Haryana (Palla, Palli, Partial load of Sector-56 and 52, Gurgaon). Faridabad generation tripped on under frequency protection. House load operation of Faridabad units didn’t occur due to problem in the logic. 220kV Badarpur U#4 & U#5 units tripped within 1800ms of fault occurrence on boiler and turbine problem. After tripping of all 220kV grid connectivity of partial South Delhi area and melting of jumper in 220kV Charkhi Dadri-BTPS line, Pragati generation islanded with the partial load of South Delhi area. The UFR and df/dt relays (all three stages) operated resulted in load shedding of the order

of 500MW in the aforesaid island. Finally island of partial South Delhi load collapsed due to load generation mismatch. It resulted into partial load loss in South Delhi area and Haryana control area. Delayed clearance of fault (FIDVR: Fault induced delayed voltage recovery) and large dip in voltage in nearby area having large AC and induction motor load resulted into stalling of induction motors/AC for few seconds and recover within few seconds to few minutes. Similar type of load reduction (~3750MW) also observed on 18.05.2016, during tripping of 400kV Bawana-Mundka ckt-2 on Y-B phase to phase fault. A summarized list of such load reduction events in NR (Northern Region) is attached as Annex-1. Due to actual load loss and stalling of induction motors, sudden load reduction occurred on 765kV Agra-Gwalior D/C line. Power flow on 765kV Agra-Gwalior reduced from 1212MW to 470MW per circuit and it resulted into triggering of case-2 of SPS (System protection scheme). SPS scheme, designed load loss and generation backing down details for 765kV Agra-Gwalior SPS attached as Annex-2.

B. Antecedent Connectivity:

Fig1: 220kV Samaypur (BBMB) station

Fig2: Antecedent connectivity in the nearby area of 220kV Samaypur (BBMB) station

Fig3: Connectivity diagram of 220kV BTPS and partial South Delhi Load Island

In antecedent condition, 220kV Samaypur-Palwal ckt-1 connected on Bus-1. 220kV Samaypur-Palwal ckt-1 & 2 radially feeding the load at 220kV Palwal station. Bus

coupler at 220kV Palwal station was in open condition. At 220kV Badshahpur station bus coupler was in open condition and 220kV Samaypur

DC (double circuit), IMT Manesar DC, 100MVA transformer-1 and 3 were connected at Bus-1. 220kV Palli DC, Manesar(PG) DC, 100MVA transformer-2 and 4 were connected at Bus-2. In antecedent condition, 220kV Palli-Badshahpur DC was under open condition and 220kV Badshahpur-Palli DC was under open condition.

220kV Samaypur-Badsahpur ckt1&2 along with 100MVA ICT-1 and 3 were radially connected at 220kV Samaypur (BBMB).

There was a problem in 220kV Bus Coupler at Sector-56 Gurgaon i.e. Sector-56 and 52 loads is segregated into two parts and radially fed from 220kV Palli and Sector-72, Gurgaon.

Prior to the incident, Pragati Station (Unit-1 & STG) was connected to BTPS side through 220kV Sarita Vihar - BTPS Ckts. 220kV Bus coupler was open at Pragati S/Stn.

BTPS Units #4 & #5 were connected to grid through 220kV BTPS – Ballabgarh Ckts, 220kV BTPS – Alwar Ckt. & 220kV BTPS – Mehrauli -Dial-Bamnauli Ckts. 220kV Bus Coupler was closed at Mehrauli.

All 220kV lines from Samaypur (BBMB) were intact. One module of steam turbine and gas turbine at Faridabad Gas Station was running with

~150MW generation. Two units of BTPS were running with ~360MW generation. 765kV Agra-Gwalior power flow was ~1200MW each circuit from West to North.

C. Antecedent conditions in NR grid (at 14:27hrs): Grid Frequency : 49.94Hz NR Demand : 45928MW Net Inter Regional Import : 6648MW HVDC Rihand-Dadri Flow : 700MW HVDC Balia-Bhiwadi Flow : 1200MW Vindhyachal BtB Flow : 240MW (North to West) Agra-Gwalior Power Flow : 2400MW (West to North)

D. Load loss and Generation loss: Event Category: GD-1 Load Loss & Generation Loss: Load loss in the event consist of three part- actual load

loss, load loss on account of Agra-Gwalior SPS action and stalling of induction motors. Load loss and generation loss details of NR states are tabulated below:

S. No. State Generation Loss (in MW) Load Loss (in

MW)

1 Delhi 561 1450

2 Haryana 181 1515

3 Uttar Pradesh 0 1050

4 Rajasthan 0 150

5 Punjab 0 38

6 Northern Region 711 4203 Graphical plot of PMU data and SCADA data is attached as Annex-3

E. Name of the Tripped Elements: 220 KV Samaypur-Ballabgarh(BBMB) triple ckt 220 KV Samaypur-FGPP(Faridabad) ckt-1 & 2

400/220kV ICT-1,2,3&4 at Ballabgarh(PG) 400kV Ballabgarh-Gurgaon ckt. 220kV Samaypur-Palli ckt-1&2 220kV Samaypur-Palwal ckt-1&2 220kV Samaypur-Badsahpur ckt-1&2 220kV Faridabad-Palla D/C, One GT & ST of Faridabad Gas 220kV Ballabgarh(BBMB)-Badarpur TPS D/C One unit of 220kV Badarpur TPS (Generation-165MW) One unit of Pragati (Generation 150MW) connected radially with Sarita Vihar & Badarpur

TPS. Bus Coupler at 220kV Pragati station was in open condition for radial fed. Load at Sarita Vihar, Okhla, one bus at Meharauli Two units of Faridabad generation (One GT+ST module) Load at Palla, Palli, Badsahpur, Sector-56 Gurgaon

F. Sequence of Event: Y-phase CT busted at 220kV Samaypur (BBMB) end of 220kV Samaypur (BBMB)-

Palwal ckt-1. It resulted into failure of CBs of all three phases at Samaypur (BBMB) end of 220kV Samaypur-Palwal ckt-1. CT damage report is attached as Annex-4.

Bus Bar Protection for Bus-1 of Samaypur (BBMB) didn’t operate on bus fault. The Faridabad (FGPS)-Palla ckt-2 was the first to trip of all the four (220KV Samaypur-1,

2, Palla-1 & 2) outgoing feeders at Faridabad. It tripped from FGPS end by operation of Distance protection on receipt of PLCC carrier. However PLCC of this line was under outage. Carrier protection scheme may be mal-operated at Faridabad (FGPS) end.

220kV Faridabad-Samaypur ckt-1 and ckt-2 tripped from Faridabad end in Z-2 timing. 220kV Samaypur-Badshahpur DC was radially fed the load of Badshahpur area however

220kV Samaypur-Badshahpur ckt-1 tripped from Badshahpur end due to loop flow of fault current during fault in DC line. 220kV Samaypur-Badshahpur ckt-2 didn’t trip after tripping of ckt-1 due to radial load.

220kV Samaypur-Ballabhgarh (BBMB) triple circuit tripped from Ballabhgarh (BBMB) end in Z-2 or Z-3 time.

220kV Samaypur-Palli ckt-1 and 2 tripped from Palli end in Z-2 or Z-3 time. 220kV Samaypur-Palwal ckt-1 & 2 were radially feeding the load of Palwal area. After

tripping of 220kV Samaypur-Palwal ckt-1, 220kV Samaypur-Palwal ckt-2 remained intact in the system and manually opened later on. DR didn’t trigger for low voltage during fault condition.

Z-3 distance protection of 400kV Gurgaon-Ballabhgarh line operated from Gurgaon (PG) within 1400ms of occurrence of fault.

400/220kV ICT-1, 2, 3 and 4 of Ballabhgarh (PG) tripped on backup over current protection from 400V side. Last ICT (ICT 03) tripped within 1800ms of occurrence of fault.

Fault isolated from the system after tripping of 400/220kV ICT-03 of Ballabhgarh (PG).

Summarized Sequence of Event for complete event is tabulated below:

S.No. Time (in hrs)

Reference time

(in sec) Description Remarks

1 14:27:17,535 0 Samaypur‐Palwal‐1 Reference time from PMU

2 14:27:17,600 65 Y‐phase to earth fault Y‐phase CT failure at 220kV Samaypur (BBMB) end of 220kV Samaypur‐Palwal ckt1

3 14:27:17,720 185 Y‐phase to earth Fault cleared

4 14:27:18,680 0 3‐ph fault

Reference time from PMU (Failure of all three CB of Samaypur (BBMB) end of 220kV Samaypur‐Palwal ckt1)

5 14:27:18,770 90 FGPP‐Palla‐2

6 14:27:18,990 310 FGPP‐Samaypur‐2

7 14:27:19,000 320 FGPP‐Samaypur‐1

8 14:27:19,315 635 Badshahpur‐Samaypur‐1

9 14:27:19,715 1035 Bus coupler at Samaypur

10 14:27:20,030 1350 400/220kV ICT‐1 of Ballabhgarh (PG) Backup over current protection operated

11 14:27:20,064 1384 400kV Gurgaon‐Ballabhgarh ckt Line tripped in Z‐3 from Gurgaon end prior to ICT tripping at Ballabhgarh(PG)

12 14:27:20,245 1570 400/220kV ICT‐2 of Ballabhgarh (PG)

Backup over current protection operated 13 14:27:20,250

14 14:27:20,275 1595 400/220kV ICT‐4 of Ballabhgarh (PG) Backup over current protection operated

15 14:27:20,450 1770 Fault cleared, 400/220kV ICT‐3 of Ballabhgarh (PG)

Backup over current protection operated

16 14:27:21,985 3305 Unit #4: Badarpur TPS After tripping of Badarpur Generation load on MIA and Charkhi Dadri feeder increased 17 14:27:22,100 3420 Unit #5: Badarpur TPS

18 14:27:27,730 9050 Unit #1: Faridabad Faridabad Generation islanded with the load of Palla, Palli and 220kV Sector‐56 and finally generation tripped on under frequency due to load generation mismatch in the island

19 14:27:27,740 9060 Unit #2: Faridabad

20 14:29:15,445 ~ 2 min Bus coupler at Mehrauli Bus coupler at Mehrauli opened manually due to high loading on 220kV Bamnauli‐DIAL DC

21 14:32:43,846 ~5min 220kV MIA‐BTPS (MIA end) Exact time not available. This line manually opened from MIA end

22 14:32:46,895 ~5min 220kV Charkhi Dadri‐BTPS (Charkhi dadri end)

df/dt operation observed in Delhi Island and shed the load of ~500MW

23 14:33:‐‐,‐‐‐ ~6min UFR and df/dt operation in Delhi Island Time synchronization problem in UFR and df/dt relays

Island operation of Faridabad Generation: Faridabad Gas Power Station (FGPS) is connected with DC Palla (HVPNL) and DC

Samaypur (BBMB) respectively. GT-2 was running on Gas Fuel with Steam turbine at 118 and 63 MW load respectively.

After tripping of 220kV Samaypur-Palli DC and Samaypur-Faridabad DC, Faridabad generation becomes islanded with the load of Palla, Palli and partial load of Sector-56 & 52.

This island could not survive and collapsed within 10sec due to more load remaining connected than the generation at FGPS.

GT-2 terminal voltage at FGPS dropped to 3.8KV (10.5kV normal) and the 6.6kV switchgear voltage dipped to 2.6kV. Palla being load centre, always draws power from FGPS and with its isolation from Palli, entire load shifted to FGPS. As a result of higher load than generation, frequency dipped to 47.32 Hz and 220kV HVCB of GT-1&2 opened with Under Frequency protection.

Logic:

Gas Turbine Unloading and Protection Shutdown took place as Channel fault appeared

in GT-2 due to line current (in Transducer) in R, Y and B phases exceeding full scale. This logic (shown above) led to the initiation of Shutdown of Gas turbine-2. As soon as HVCB of GT-2 opened due to under frequency, its UAT incomers also opened as per logic. This logic prevented the running GT to come on House Load.

Island operation of partial South Delhi Load: After multiple element tripping at 220kV Samaypur (BBMB), partial load of South Delhi

area was being fed from 220kV BTPS Generation, 220kV Pragati Generation and import from 220kV MIA, 220kV Charkhi Dadri and 400/220kV Bamnauli (PG).

Badarpur U#4 & U#5 was running with load of 195 & 207 MW but both units tripped after 1800ms of fault occurrence. Both the unit tripped due to boiler and turbine problem.

HVCB OPEN 12ADA01G5001 GT Transfer B/C OPEN 12ADA01G5014M OR-gate

GCB OPEN 12MYB01EC001 12BAC01G5001 Emergency s/d command (from Channel fault) AUTO-OFF TO UAT INCOMERS

≥I

AND

Root Cause & GPS time of tripping could not be pin pointed due to non-availability of SOE, time synchronized DR and Event logs.

After tripping of Badarpur Generation of ~400MW, generation in South Delhi area became 200MW and load of ~900MW. It resulted into exceeding the import on grid connected 220kV lines.

Due to increase in the loading of 220kV Mehrauli-DIAL D/C, 220kV Bus coupler at Mehrauli station manually opened by operational staff. It further increased the power flow on remaining 220kV lines (220kV Charkhi Dadri-BTPS and MIA-BTPS).

220kV MIA-BTPS also manually opened from MIA end due to increase in the line loading and it resulted into very high loading on 220kV Charkhi Dadri-BTPS line.

220kV Charkhi Dadri-BTPS power flow increased upto 900-1000Ampere and line finally tripped due to melting of jumper.

After tripping of only grid connected source for partial south Delhi Island, generation load mismatch observed in the island and it resulted into operation of defense mechanism for the island. All three stages (Stage-1, 2 and 3) of df/dt(Rate of change of frequency) Relay and UFR (Under Frequency Relay) operated in the island and shed the load of ~500MW.

Finally Pragati generation also tripped and partial blackout occurred in south Delhi area. Load shedding due to stalling of induction motors and Case-2 operation of 765kV Agra-Gwalior SPS Scheme: Load shedding in the Delhi NCR area due to stalling of induction motors due to dip in the

voltage. It resulted into steep rise in the frequency and df/dt relay may be operated. Member from Rajasthan informed that similar type of outage due to dip in the voltage

also occurred in Rajasthan for 33kV and 132kV loads of chemical and textile industries. Industrial machine tripped during transient dip in the system voltage.

Due to actual load loss and stalling of induction motors, sudden load reduction occurred on 765kV Agra-Gwalior SPS. Power flow on 765kV Agra-Gwalior reduced from 1212MW to 470MW per circuit and it resulted into operation of Case-2 of Agra-Gwalior SPS scheme. Case-2 operation shed the NR (Northern Region) load in C, D, E, F group and generation backing down in Korba, Vindhyachal and Mundra of WR (Western Region).

Case-2 of Agra-Gwalior SPS scheme design to cater the tripping of both 765kV Agra-Gwalior lines from remote end but in this condition actual load reduction occurred on these lines without tripping of line and Case-2 operated. This logic of power flow took due to non-availability of proper OPGW connectivity between these two stations.

G. Restorations:

S. No. Element Name Type Voltage Level Owner Time of tripping

Revival Date

Revival Time

1 Ballabhgarh‐Gurgaon Line 400 kV PGCIL 14:27 09‐06‐16 14:52

2 Ballabhgarh 315 MVA ICT 2 ICT 400/220 kV PGCIL 14:27 09‐06‐16 16:08




6 Ballabhgarh(BBMB)‐Samaypur(BBMB) ‐ 2 Line 220 kV BBMB 14:27 09‐06‐16 16:16

7 Palwal(HVPNL)‐Samaypur(BBMB) 2 Line 220 kV BBMB 14:27 09‐06‐16 16:50

8 Palwal(HVPNL)‐Samaypur(BBMB) 1 Line 220 kV BBMB 14:27 03‐07‐16 15:30


10 Faridabad(NTPC)‐Palla(HVPNL) 2 Line 220 kV PGCIL 14:27 09‐06‐16 15:32

11 Faridabad(NTPC)‐Palla(HVPNL) 1 Line 220 kV PGCIL 14:27 09‐06‐16 15:31


13 Ballabhgarh(BBMB)‐Ch.Dadri(BBMB) Line 220 kV BBMB 14:33 09‐06‐16 14:58

14 Palli(HVPNL)‐Samaypur(BBMB) 2 Line 220 kV BBMB 14:27 09‐06‐16 16:39

15 Palli(HVPNL)‐Samaypur(BBMB) 1 Line 220 kV BBMB 14:27 09‐06‐16 16:36

16 Badarpur(NTPC)‐Ballabhgarh(BBMB) 2 Line 220 kV BBMB 14:27 09‐06‐16 15:30

17 Badarpur(NTPC)‐Ballabhgarh(BBMB) 1 Line 220 kV BBMB 14:27 09‐06‐16 15:29

18 Badshahpur(HVPNL)‐Samaypur(BBMB) 2 Line 220 kV BBMB 14:27 10‐06‐16 22:28

19 Faridabad(NTPC)‐Samaypur(BBMB) 1 Line 220 kV PGCIL 14:27 09‐06‐16 16:11

20 Faridabad(NTPC)‐Samaypur(BBMB) 2 Line 220 kV PGCIL 14:27 09‐06‐16 16:20

21 Badshahpur(HVPNL)‐Samaypur(BBMB) 1 Line 220 kV HVPNL 14:27 09‐06‐16 16:57

22 Ch.Dadri(BBMB)‐Samaypur(BBMB) Line 220 kV BBMB 14:27 09‐06‐16 16:29

H. Remedial action already taken and report submission:

Z-3 time delay at 400kV Gurgaon (PG) end of 400kV Gurgaon-Ballabhgarh line increased to 2.5 second from 1000ms.

Faulted CT and CB’s have been replaced at 220kV Samaypur(BBMB) for 220kV Samaypur-Palwal ckt-1.

Detailed Report submitted by BBMB is attached as Annex-5 and Annex-5.1

I. Report Submission:

Detailed Report submitted by BBMB is attached as Annex-5 and Annex-5.1 Detailed Report submitted by Delhi is attached as Annex-6 and Annex-6.1 Detailed Report submitted by NTPC is attached as Annex-7 Detailed Report submitted by POWERGRID is attached as Annex-8

J. Recommendations: Faulted CT at Samaypur (BBMB) was commissioned in year 1989. Measured tan delta

value for this CT was 1.47. It was recommended by BBMB to replace the CT (Reference: BBMB letter to HVPNL). Frequency of C and tan delta test may be increased to quarterly for equipment having more than useful life or poor results in previously conducted tests. (General Recommendations)

CT failure observed in many events at 220kV Samaypur(BBMB). Committee recommends C and tan delta test for all the CTs at 220kV Samaypur(BBMB) station and report to be submitted to RPC/RLDC. BBMB may also submit the copy of letter sent to HVPNL and plan for replacement of CTs(with poor result) at 220kV Samaypur (BBMB). (Action: BBMB, HVPNL; Time Frame: 30 days)

Agenda may be put in next PSC meeting for discussion on factors (results of test, age, increase in C tan delta value etc.) for CT replacement and type of CT (live tank or dead tank CT) to be used in the system.

Availability and Healthiness of numerical Bus Bar Protection at 220kV Samaypur (BBMB) needs to be ensured. (Action: BBMB; Time Frame: 30 days)

Detailed report of load loss on account of stalling of motor and Agra-Gwalior SPS operation may be submitted. Utilities may also submit the incident report including load loss/industry outage reported due to voltage dip. (Action: Haryana, Rajasthan, Uttar Pradesh, Punjab and Delhi; Time Frame: 7 days)

Delhi may review the Delhi islanding scheme to prevent unsuccessful real time operation, take remedial measures and submit the report to RPC/RLDC. (Action: Delhi; Time Frame: 30days)

To prevent manual opening of bus coupler at Mehrauli, an SPS scheme for line loading at 220kV Bamnauli-DIAL-Mehrauli feeders to be devised and submitted to NRPC for approval. (Action: Delhi; Time Frame: 30 days)

220kV MIA-BTPS line is important tie line between Delhi and Rajasthan and it is also an important grid element of NR. Standing instruction shall be issued to station personal for non-opening of 220kV MIA-BTPS line without prior information to NRLDC.. (Action: Rajasthan, Delhi; Time Frame: 7 days)

Problem of issuance of trip command with the receipt of carrier by P437 distance relay at FGPS needs to be resolved at the earliest. (Action: NTPC; Time Frame: 7 days)

House Load operation logic of Faridabad GPS may be checked and corrected for successful operation. (Action: NTPC; Time Frame: 15 days)

Islanding operation of FGPS may be reviewed for successful operation. Haryana/NTPC may implement the remedial measures and submit the report to RPC/RLDC. (Action: Haryana, NTPC; Time Frame: 30 days)

POWERGRID may identify the exact reason of tripping of 400kV Gurgaon-Ballabhgarh in Zone-3 over reaching the ICT backup over current protection and submit the report to RPC/RLDC. (Action: POWERGRID, Time Frame: 15 days)

Palli-Sector-56, 52, 72 and Palli-Badshahpur connectivity may be put in loop for reliable power supply to the customer. Healthiness of bus coupler at 220kV Sector-56 should be ensured. (Action: Haryana, Time Frame: 15 days)

Provision of uninterrupted power supply to SoE, all recorders etc. at BTPS to ensure stamping of all event / alarms with GPS time. (Action: NTPC; Time Frame: 30 days)

Time synchronization of all Numerical Relays at 220kV BTPS, FGPS switchyard and Samaypur (BBMB). (Action: NTPC, BBMB; Time Frame: 15 days)

Time synchronization of Numerical Relays at 400kV Gurgaon & Ballabhgarh(PG). (Action: POWERGRID, Time Frame: 15 days)

Time synchronization of all Numerical Relays (UFR and df/dt relay) at different switchyard of south delhi area having UFR and df/dt relays. (Action: Delhi; Time Frame: 15 days)

Availability of digital and analog data of 220kV Samaypur (BBMB), Palla, Palli, Badshahpur, Palwal, BTPS, Faridabad and MIA need to be ensured. (Action: BBMB, HVPNL, Rajasthan, NTPC; Time Frame: 30 days)

DR may be triggered for under voltage so that in case of sustained low voltage at any station could be captured in DR. (General Recommendations)

Sd/- Sd/-

Rajiv Porwal M.K.Singhal

AGM, NRLDC SE, RRVPNL Sd/-

Hemant K. Pandey SE, NRPC

Annex-1

S. No.

Date Event Details

Fault Clearance Time (in mili

second)

Region

Quantum of load

Reduction (in MW)

Remarks

1 24.09.13 Three phase fault in 400kV Dadri‐Muradnagar line

100ms Northern Region

1085MW

SLDC Delhi reported the tripping of 11kV feeders on operation of over current protection

2 31.05.15

At 01:17 Hrs due to damage in disc spring of Y‐ph Jack Bus of 400kV Bus‐Coupler bay at G. Noida S/S. It resulted into bus fault for the system. 400kV Dadri‐G. Noida and G. Noida‐Nawada tripped from remote end of G. Noida in zone‐2


1700MW

SLDC Delhi reported the tripping of 11kV feeders on operation of over current protection

3 12.10.15

Due to R phase CT blast occurred at 220kV Samaypur (BBMB) Sub Station. Both 220kV Samaypur circuit tripped on zone 2 protection


1500MW

SLDC Delhi reported tripping of the feeders on Under Frequency protection

4 18.05.16 Y‐B phase to phase fault in 400kV Bawana‐Mundka ckt‐2


3750MW

No information received for load reduction in Northern Region

5 09.06.16

Y‐phase CT of 220kV Samaypur‐Palwal ckt‐1 busted. All the connected 220kV feeders tripped from remote end in Z‐2/Z‐3. 400/220kV ICTs at Ballabhgarh tripped on backup over current/ earth fault protection. BTPS, Faridabad Gas & Pragati Gas generation also


3492MW

SLDC Delhi reported tripping of the feeders on Under Frequency & islanding protection operation (479MW in Delhi)

tripped.

Annex-2

SPS for WR-NR corridor - 765kV Agra-Gwalior D/C

Case Contingency Action

Case-1

Reduction of import by NR on 765 kV Agra-Gwalior ckt-I & II by more than 1000 MW but less than 1500 MW

Shed loads in Groups C and D in the Northern Region

Case-2

Reduction of import by NR on 765 kV Agra-Gwalior ckt-I & II by more than or equal to 1500 MW

Action-1 Shed Loads in Groups C, D, E & F Action-2 Automatically back down 500 MW generation in Western Region in the shortest possible time. (Korba, Vindhyachal, CGPL Mundra stations)

Case-3

Total steady state flow on 765 kV Gwalior to Agra in case both ckt is in service more than 2500 MW for a period of 10(ten) seconds or b. flow on 765kV from Gwalior to Agra when only one ckt is in service more than 1800 MW for a period of 5 ( five) seconds OR Steady State voltage at 400 kV Agra less than 380 kV& more than 50kV for a period of 10(ten) seconds (direction of power flow is West to North)

Shed load in Group C and D

Remark:

1. Load Shedding shall be achieved within 500ms, including all signal

propagation/breaker opening time delay.

2. Load shedding in Western Uttar Pradesh, Rajasthan, Punjab and Haryana area

Delhi UP Rajasthan Haryana Punjab

Sl.

No.

Group

Load Planne

d Load

(MW)

Load Planne

d Load

(MW)

Load Planne

d Load

(MW)

Load Planne

d Load

(MW)

Load Planne

d Load

(MW)

Group

Total

1

Group‐A

Mandaula(PG

)‐220 kV

Mandaula‐

Narela D/C

150

Feeders from

220/132 kV

Muradnagar

old s/s

100 220/132 kV Bagru‐

132 kV GSS

Bagru

25

220/66 kV

Malerkotla‐ 66 kV

Malerkotla ckt ‐66

kV Naudhrani ckt

35 310

2

Group‐B

Mandaula(PG

)‐220 kV

Mandaula‐

Gopalpur

200

220/132 kV

Ratangarh‐ 132

kV GSS

Momasar

26 Panipat (BBMB)‐

1x100 MVA,

220/33 kV ICT at

Panipat

50

276

3

Group‐C

Feeders from

220/132 kV

Modipuram

substation

100 220/132 kV Kota‐ 132

kV Baroli; 220/132 kV

Bhilwara‐ 132 kV GSS

Hamirgarh

60

Samaypur(BBMB)‐

220 kV

Samaypur‐Palwal

D/C

50

220/66 kV Gobindgarh‐1

‐66 kV Chourwala ckt

‐66 kV Talwara ckt‐1

71

281

4

Group‐D

220/132 kV Alwar‐

132 kV GSS Bansoor,

132 kV GSS Ratangarh

59 Samaypur(BBMB)‐

220 kV Samaypur‐

Badshahpur D/C

90

220/66 kV Laltokalan

‐66 kV Gill Road ckt‐1

‐66 kV Gill Road ckt‐2

‐66 kV Ferozpur Road ckt

90

239

5

Group‐E

220 kV

Mainpuri ‐ 2 x

132/33 kV, 40

MVA T/F (20

MW‐60MW)

50

220/132 kV Alwar‐

132 kV GSS

Malakheda; 220/132

kV Bhilwara‐ 132 kV

GSS Gangapur, 132 kV

GSS Danta, 132 kV GSS

Devgarh and 132 kV

GSS Kareda; 220/132

kV Merta‐132 kV GSS

Kuchera

100

132 kV PTPS‐

132 kV PTPS‐Chanduali

132 kV PTPS‐Munak

50

220 kV Jamsher

‐66 kV Nakodar Road‐1

‐66 kV Nakodar Road‐2

100

300

6

Group‐F

220 kV Nara‐

132/33 kV, 40

MVA T/F and

132/33 kV, 63

MVA T/F

(32MW‐52MW)

50

220/132 kV Alwar‐

132 kV GSS

Alwar(local load);

220/132 kV Merta‐

132 kV GSS Lamba,

132 kV GSS Golan

100

132 kV Narwana

132 kV Narwana‐Garhi

132 kV Narwana‐Tohana

132 kV Narwana‐Uklana

132 kV Narwana‐

Dhamtansahib 132/33

kV T/F 20 MVA

132/11 kV T/F 8MVA

75

220 kV Mohali

‐66 kV Mohali ckt 1&2

‐66 kV Mohali ckt 3&4

100

325

7

Group‐G

400/220 kV

Ratangarh‐ 220 kV

GSS Sujangarh, and

220/132 kV

Ratangarh‐ 132 kV

GSS Sardarsahar

100

132 kV Dadri

132 kV Dadri‐

Dadri city 132 kV

Dadri‐Matenhail

132 kV Dadri‐Kalanaur

132 kV Dadri‐

Bahu 132/33kV

T/F 20/25 MVA 132/33kV T/F 16/20 MVA

75

220 kV Ablowal

‐66 kV Rakhra‐1

‐66 kV Rakhra‐2

‐66 kV Rakhra‐3

‐66 kV Rakhra‐4

100

275

TOTAL 350 300 470 390 496 2006

Fig 1 Load Details

Annex-3

Graphical plots:

Fig. PMU plot of phase voltages

Fig. PMU plot of Frequency and df/dt

Annex-4

Performa for Details of failure of equipment

1. Name of Substation: - 220kV Samaypur (BBMB)

2. Utility/Owner of Substation: - BBMB

3. Faulty equipment: - Y-Phase CT of 220 KV Samaypur–Palwal-1

4. Rating:- 245 KV

5. Make:- TELK

6. Serial no:- 230160-02

7. Year of manufacturing:- 1989

8. Year of commissioning:- 05.01.1990

9. Date and time of occurrence of fault:- 09.06.2016 at 14:27 Hrs.

10. Fault discovered during O&M:- Nothing.

11. Present condition of equipment:- Burst.

12 Detail of previous maintenance:- 14.03.16 on P.T.W No-6

IR Value 103 G ohm

Tan delta (12.03.15): 1.47 %

13 Detail of previous failure:- Nil

14 Description of fault:- At 21:47hrs Red phase CT of 220 KV Samaypur-Palwal -1 burst and caught fire consequently led to the bus Fault.

15. Detail of tests done after failure:- CT burst and caught fire.

16. Conclusion/ recommendation:- Recommended for replacement.

report of the group on tripping of multiple trippings in ... report.pdf · report of the group on...

Documents